The worsening migrant situation on the European continent has sparked reports of refugees attempting to stowaway on the horseboxes of top show jumping riders as they navigate the Channel Tunnel entry and ferry port in Calais, France.

The 30-mile tunnel also known as the “Chunnel” goes under the English Channel and, in addition to the ferry crossing, is one of the main arteries linking the United Kingdom to the European continent. In recent months, migrants and refugees have gathered at the French entrance of the Chunnel and the above ground ferry port with escalating intensity as they seek any means possible to get to the UK.

Robert Whitaker reported on his Facebook page on Sunday that as he was driving his horses back from the CSI4* at Liege, a group of refugees placed a large wooden bollard in the road to slow traffic, and then attempted to board his horsebox when he stopped to allow his father, famed show jumper John Whitaker, out to clear the way. The refugees got as far as taking the back ramp of the horsebox down. Robert and John drove away with the ramp still down, creating a nervewracking situation for all. The Whitakers safely boarded the Channel ferry to make their crossing, but two hours later, the groom of Shane Breen approached the same crossing and a group of refugees were able to enter her horsebox through the side door. While the police were called, it was fellow lorry drivers came to the groom’s aid to help kick the refugees out of the horsebox, and luckily, no harm came to the horses inside.

Other grooms and riders have reported similar incidents, including dressage star Charlotte Dujardin’s groom Alan Davies, who discovered a migrant hanging onto the chassis underneath his horsebox at the same crossing, and a Belgian horsebox that ran into a similar scenario in July.

Refugees desperate to gain entry to the UK may not consider the fact that live, not to mention valuable, animals are tied inside the boxes they’re attempting to open. Locking the back ramps and side doors of horseboxes is highly recommended, and grooms and drivers should consider traveling together in groups in order to watch out for each other.

Using the Chunnel tunnel and ferry crossing to transport showjumpers back and forth from the UK will continue to be a necessary means of transportation as the 2015 competition season winds down through December, with CSI5* events scheduled on both sides of the English Channel.